try regular grooming for healthier turf

jacobsen's patented turf groomer enhances vertical growth

M.C. Engelke, Ph.D, is a professor and faculty fellow at the Texas Agricultural Experiment Station in Dallas, which is an agency of the Texas A & M University System. He is also a consultant to Jacobsen, specializing in the identification, production and maintenance of turf grass. Here, Engelke discusses the benefits of turf grooming. Jacobsen is the only equipment manufacturer with a patented Turf Groomer.

Closeup shows the new buds developing from the true crown. Grooming was initiated on this Zoysia turf approximately eight weeks prior.

Simply put, turf grooming is a means of managing the growth habit of turf to provide for a high-quality, healthy plant. The process uses narrow vertical blades (thin kerf) to periodically clip the advancing growing point of turf grass.

It is important to distinguish grooming from vertical mowing. Both processes use vertical blades, but from a biological standpoint this is where the similarities end. Verticutters use rotating vertical blades, which penetrate deep into the crown area of the plant, and possibly below, severing stolons and stems. This generally provides an effective means of reducing or removing thatch.

The groomer is a lightweight version of the verticutter. Groomers help reduce grain and lift turf for a cleaner cut. Agronomically, this is accomplished by setting the blades at or slightly above the height of cut (bedknife setting). From a biological standpoint, however, adjusting the blades to just below the height of cut (initially not to exceed 10 percent below the bedknife) provides stimulus to the plant to initiate new growing points. The rotating vertical blades actually sever the expanding clum, remove the plant apex (growing point) and force the crown to generate a new bud.

Grooming is light scalping

Turf grooming can be compared to light scalping, but on a much-reduced scale. Using 1/2-inch spacing between vertical blades that are 1/8 inch thick results in approximately 3 to 5 percent of the clums being clipped during each mowing. Each grooming “scalps” a fraction of the turf, which is staged in a timed recovery response.

By repeatedly using groomers the entire turf community is eventually forced to be in a rejuvenated state with new growth from the crown of the plant. Grain occurs when the clum or stem is allowed to elongate and “lean” a particular direction with the growing point at the cut end of the stem. If the stem is removed periodically and new growth is initiated from the base (crown) of the plant, the subsequent growth is forced to be more vertical and less prone to developing a grain and less prone to scalping.

Change growing point position

Besides altering the way the plant grows, the position of the growing point is also changed. With the extending stem being severed (scalped), the plant will initiate new growing points at the crown. Repeated mowing with turf groomers encourages and conditions the plant and turf to grow tighter to the soil, making for a firmer, more open canopy. This open canopy aids in the escape of excess moisture and provides a healthier, more resilient turf.

Overseeding requires grooming

Turf grooming can be especially critical prior to overseeding. When ambient air and soil temperatures drop in fall, the plant begins to store carbohydrates in the roots, rhizomes and stolons. This helps in winter survival and spring green-up and transition. With the acceptance of overseeding base grasses (warm season) with a cool season grass such as Poa trivialis or perennial ryegrass, it has been a standard practice to heavily verticut and even scalp the turf.

Scalping is accomplished with either a verticutter, flail mower or reel mower set low enough to remove excess plant materials. Not only is this a laborious task, but it also disrupts the course, creates considerable debris that must be removed and, more importantly, reduces the plant’s ability to store additional carbohydrates for winter survival. In many cases it will also force the plant to use much of its stored carbohydrates just to finish out the fall growing season.

A three-year grooming study resulted in improved turf health, fall color retention and spring green-up. The need for extensive fall preparation for overseeding was reduced, providing a superior turf both in the fall and spring transition with improved winter survival. In short, grooming is a proactive cultural practice which supports maximum turf health and performance throughout the year when done routinely. All stoloniferous and rhizomatous turfs have been demonstrated to benefit from routine grooming regardless of the height-of-cut — greens, tees, fairways or sports fields.